Modern vehicles are increasingly equipped with driver assistance systems. These driver assistance systems support a vehicle driver in flowing traffic or when parking the vehicle at the edge of the road, for example. For the determination of target parameters such as distance and relative speed of an object, radar systems have proven useful which work with modulated signals. By a suitable selection of the modulation method, an accurate estimation of the target parameters and also the separation of individual targets are possible on the basis of these parameters.
For the angular estimation of the target parameters various types of antenna are used. Besides classical systems scanning in parallel, switched antenna concepts are also increasingly of interest for this purpose. For instance, German document DE 10 2009 029 503 A1 discusses a radar sensor device having a planar antenna device which has a plurality of vertically aligned antenna gaps in the form of a thinned-out array.
For the operation of switched antennas, the time division multiplex method is suitable, for example, in which the switched antennas are used one after the other. In this context, however, a possible movement of the target objects must also be taken into account.
There is therefore a need for a radar device having a switched antenna array, which permits short time intervals between the individual switching states. There is further a need for a radar device which enables a phase evaluation over the various switching states of a utilized antenna array.